Full multinuclear magnetic resonance analysis of 2,4‐dinitrofluorobenzene

The complete assignment of the high‐resolution NMR spectra 2,4‐dinitrofluorobenzene was made, including the 1H, 13C, 15N, 17O and 19F nuclei. The 13C,19F, 13C,1H, 15N,19F and 15N,1H one‐bond and long‐range coupling constants were determinated and the signs were obtained by means of two‐dimensional correlation spectroscopy: 1H–1H‐COSY, 13C–1H‐COSY, 13C–1H‐COLOC and 1H–15N, 19F–15N and 19F–13C HMQC. The spin–lattice relaxation times of 13C revealed their anisotropy components and it was evident that the dipole–dipole contribution of fluorine was an efficient mechanism for C‐1 relaxation. The T1s of 1H agreed with the classical description: at low temperature the main contribution is dipole–dipole relaxation and at high temperature the relaxation is dominated by the spin–rotation mechanism. A linear relationship between δ13C(exp) and σC using GIAO (hybrid functional B3LYP) was found. 3J(13C, 1H) and the 1J(13C, 13C) have a relationship with the delocalization energies estimated by the NBO approach.